Internal combustion engine



s p 1934- J. H. GEISSE 1,972,881

INTERNAL COMBUSTION ENGINE Filed Nov. 14, 1929. 3 Sheets-Sheet l FI QI.

. INVENTOP. 7

Sept. 11, 1934. J. H. GEISSE 1,972,881

INTERNAL COMBUSTION ENGINE Filed Nov. 14, 1929 3 Sheets-Sheet 2 INVENTOQ BLHMMW Sept. 11, 1934. J 51555 INTERNAL COMBUSTION ENGINE Filed Nov. 14, 1929 3 Sheets-Sheet 3 NVENTOIQ Wflwa 5 5 am til/12v Patented Sept. 11,1934

UNITED STATES PATENT OFFICE f 9 Claims.

(Granted under the act of Mai-ch 3, 1883, as

mended April 30, 1928; .370 0. G. 757) My invention relates broadly to internal combustion engines of the auto-ignition type, and more particularly to their fuel injector systems.

An object of the invention is the provision of a fuel injector system that is eflicient in operation, simple in construction, cheap to manufacture, and

easy to install.

With the above and other objects in view the invention consists in the construction, combina-' tion and arrangement of parts as will be describedmore fully hereinafter.

Reference is to be had to the accompanying drawings forming a part of this specification, in which like reference characters indicate corresponding parts throughout the several views,

and in which:

Figure 1 is a top view of a cylinder of an internal combustion engine, partly in section the fuel injection nozzle,

Figure 2 is a section through the center a cylinder and the injection mechanism,

7 Figure 3 is a view similar to Figure 1 of a slightly modified form of cylinder,

Figure 4 is a section through the center line ofthe cylinder illustrated in Figure 3,

Figure 5 is a top view of a cylinder in a further modified form, and

Figure 6 is a section on the center-line of the cylinder illustrated in Figure 5.

20 line of of the drawings, the numeral 1 indicates a cylinder of an internal combustion engine in which piston 2 operates. The cylinder head is provided with an auxiliary chamber. 6, hereinafter called the pressure chamber, which communicates with the combustion chamber of the cylinder through a port 20. Piston 3 which actuates the fuel injection plunger and is designated the actuating piston, has a threaded stem 4 and reciprocates in the pressure chamber 6 with a clearance sufficient to permit leakage of pressure past it. Movement of the piston 3- into chamber 6 causes a deflection in leaf spring 7 that is secured to the threaded stem 4 by clamping nuts 5, one on either side of the spring. It is to be understood, however, that this precise arrangement need not be practiced, as any desirable manner of securing the stem and springs together may be employed. The ends of the spring rest on blocks 8 that are movable towards or away from each other through the agency of screws 9 in order to vary the effective length of the spring.v Piston 12 operates in a fuel pump chamber 10 and is held in contact with the stem of piston 3 by a spring13 seated in the chamber 10. One end of the spring litbears. I against the end of the fuelpumpchamber andtheother end against a flange 22 carried by the piston 12. The fuel inlet 21 to' the fuelchamber and'the. discharge line 14 from the fuel chamber are each;

150 provided with suitable check valves 11. The disto show 7 Referring more particularly to Figures 1 and 2.

charge line 14 leads to an injection nozzle 15 in the cylinder 1.

The system disclosed in Figures 3 and 4 is the same as that shown in Figures 1 and 2 with the exception that the bore of the pressure chamber 6 is tapered to provide a. predeterminable leakage path past the piston 3.

In Figures 5 and 6 is shown a means for ad-- justing the leakage path about the piston 3. This means consists of a needle valve 18 operating in a passageway 19 leading from the chamber 6 to the cylinder 1. In this adaptation adjustment of the amount of air under compression permitted to leak into the chamber 6 from cylinder 1 may belobtained by the proper regulation of the needle va W.-

The operation of the device is as follows:

When the main piston 2 starts on its compression stroke the pressure on the side 17 of the actuating piston 3 increases faster than the pressure on the side 16. The difference inpressure on the two sides of the actuating piston causes it to move into the pressure chamber 6 deflecting the spring 7. The fuel pump plunger 12 is caused to follow the stem of piston 3 by the spring 13,

and draw in a charge of fuel through the inlet line 21. In other words, as the assembly moves to the left of the drawings, the volume of piston 12 remaining in the fuel chamber 10 is progressively decreased and is replaced by fuel drawn in through line 21, otherwise a partial vacuum would be created in the chamber 10 by the removal therefrom of a part of piston 12. Correspondingly, when the assemblymoves to the right, the volume of piston 12 occupying space in chamber 10 increases and the materialoccupy g the balance'-of the space in the chamber must be compressed or be ejected through line 14 and nozzle diflerence in pressures on the two sides of the piston a function of the rate of increase of the cylinder pressure and this has a maximumvalue at about 25 before top center. When the main piston'reaches this point, that ,is, approximately. 25 before top' center, the actuating pistonis ex'-" erting itsmaximum-eflfort .but owing to inertia 'it reaches its innermost position a short time thereafter As the pressure difference-on the actuating piston faces decreases from its maxi mum at approximately25 before top .centertozero at top center,the spring (causes theinjec- However, provision of the leaktion plunger to startthe injection of fuel through the discharge pipe 14, and injection 110 .18 '15.;

whenpthepiston 2' reaches the top of fits coml i p ession st oke. e us ni c o strok s! P ton 12 may be completed in one of two ways, depending on the working cycle used in the main cylinder 1 as determined by the design and the working conditions. If the injection is complete be.- fore the end of the compression stroke a constant volume cycle will result. By proper adjustment and design of the various parts it is possible to prolong the injection and obtain a constant pressure cycle. In engines having a decrease in pressure'during combustion, the pressure difference on the faces of the actuating piston will be in such a direction as to assist in the respective stroke of the injection plunger. In addition to the injection effort due to the difference in pressures on the two faces, there is an actuating effort due to the difference in areas of the two sides of the injection piston. The ratio of these areas affects the time of start of injection, the start being earlier with increase in area difference. These conditions may be determined by the selection of the relative areas of the two faces of the actuating piston by increasing or decreasing the crosssection area of the stem 4, by increasing or decreasing the leakage of pressure around the actuating piston, and/or by the selection of springs '7 and 13 of different relative tensions. This is due to the fact that the pressure differences on the two faces of the piston 3 act with or against spring '7 in the operation of the fuel pump piston 12. The rate of injection is determined by the four factors, (1) characteristics of spring '1, (2) pressures on the two faces of the injection piston, (3) size of injection orifice, and (4) viscosity of.the fuel.

It should be noted that this system of fuel injection is a safeguard against high pressures during combustion. It will be apparent at once that a material increase in pressure could not occur. dur-' ingcombustion as the increase would stop the injection of fuel by stopping the injection stroke of the piston 12.

The control of the amount of fuel injected may be accomplished by adjustment of the eifective length of the spring 7, or any other suitable means limiting the length of the injection stroke of the piston.

After the injection stroke has been completed the injection mechanism remains stationary, until the next compression stroke of the engine when it repeats the above cycle. In four stroke cycle engines there -will, of course, be no movement of the injection mechanism during the scavenge and charging strokes. e

It will be understood that the above description and accompanying drawings comprehend only the general and preferred embodiment of my invention and that various minor changes in details.of construction, proportion and arrangement of parts may be made within the scope of my appended claims and without sacrificing any of the advantages of my invention.

The herein described invention may be manufactured and used by or for the Government of the United States for governmental purposes without the payment to me of any royaltythereon.

What I claim as new is:

1. A fuel injection system for internal combustion engines including a pressure chamber in communication with the engine cylinder, a piston operable therein with a leakage clearance past the piston, means opposing the motion of the piston into the chamber, a 'fuel injection pump, and means for utilizing the reciprocal motion of the piston to operate the pump.

manager 2. A fuel injection system for internal combustion engines including a pressure chamber extending from the engine cylinder and opening thereinto, an actuating piston operable in said chamber having a leakage clearance with the chamber wall, means opposing the motion of the said piston into the pressure chamber, and means for utilizing the reciprocating motion of the said piston to inject the fuel into the engine cylinder.

3-. A fuel injection system for internal combustion engines including a pressure chamber communicating with the engine cylinder, an actuating piston operable therein and having a leakage clearance with the walls of the chamber and means for utilizing the motion of the piston to inject fuel into the engine cylinder.

4. A fuel injection system for internal combustion engines, including a pressure chamber having one end communicating with the engine cylinder through a relatively large opening and the other end through a relatively small opening for the purpose of permitting the gases in the cylinder to flow into and out of both ends of the pressure chamber, a piston operable in the chamber, and means for utilizing the motion of the piston for injecting fuel into the engine cylinder. g I

5. A fuel injection system for internal combustion engines including a pressure chamber having one end continuously communicating with the engine cylinder through a relatively large opening and the other end through a relatively small opening for the purpose of permitting the gases in the cylinder to flow into and.

out of both ends of the pressure chamber, a piston operable in the chamber, means opposing the motion of thepiston toward the end of the chamber having the relatively small opening, and means for utilizing the motion ofthe piston to inject fuel into the engine cylinder.

6. A fuel injecting system for internal combustion engines including a pressure chamber continuously communicating with the engine cylinder through a relatively small and a relatively large opening, an actuating piston operable in said chamber, means for opposin the motion of the piston towards the relatively small opening,

a fuel pump, and a fuel pump plunger operable therein, said plunger being controlled in its move- -ment by the piston in the pressure chamber.

'7. A fuel injection system for internal combustion engines comprising a pressure chamber the diameter of which is not constant throughout its length, said chamber communicating with the engine cylinder, a piston operable in the chamber, and means for utilizing the motion of the piston to inject fuel into the engine cylinder.

8. A fuel injection system for internal combustion engines including a pressure chamber communicating with theengine cylinder, a piston operable therein, and actuated by gas pressures on its faces, and means for restricting the flow of gas to one of the faces to cause the motion of the piston to be a function of the rate of increase in the engine cylinder pressure.

9. A fuel injection system for internal combustion engines including a pressure chamber communicating with the. engine cylinder, a piston operable therein, and means for interposing I 

